The present invention disclosed herein relates to a communication system, and more particularly, to a terminal for device-to-device (D2D) communication and an interference rejection method therefor.
A D2D communication technology for use in a cellular mobile communication system enables two adjacent terminals to directly exchange data without intervention of a base station. That is, two adjacent terminals in a cellular mobile communication network may set up a D2D link with a cellular interface, and then may exchange data through the D2D link regardless of cellular communication. Such a D2D communication technology may reduce loads on a cellular mobile communication network, and may improve transmission speeds of terminals located on cell boundaries without increasing the cost of infrastructure. Furthermore, the
D2D communication technology may allow terminals located in shadow areas to access a cellular network, and may increase service capacity of a system by reducing interference.
In particular, the D2D communication technology for a cellular mobile communication system has wide cell coverage and excellent security, compared to a WiFi direct, Bluetooth or Zigbee technology. Therefore, the D2D communication technology has become more important, and has been adopted as a next-generation LTE communication standard technology candidate of the 3GPP.
According to the current state of the D2D communication technology for a cellular mobile communication system, synchronization between terminals by cellular communication should be maintained, and thus, maintenance of a cellular communication link, i.e., a downlink (DL), should be guaranteed. However, in the case of a frequency divisional duplex (FDD) cellular mobile communication terminals, D2D communication is not allowed due to difference between transmission and reception carrier frequencies. In order to overcome such a limitation, a D2D reception path may be added so that time division duplex (TDD) is used for D2D communication with the same frequency as a transmission frequency of a terminal.
However, in the case where such a terminal performs D2D communication using the same frequency as the transmission frequency in a cellular mobile communication system, the quality of the D2D communication may not be guaranteed due to interference from a terminal that performs cellular communication. Therefore, it is necessary to develop a technology for enabling a terminal that performs D2D communication to avoid interference from a terminal that performs cellular communication.